subdev/pci/pcie.c

0001 /*
0002  * Copyright 2015 Karol Herbst <nouveau@karolherbst.de>
0003  *
0004  * Permission is hereby granted, free of charge, to any person obtaining a
0005  * copy of this software and associated documentation files (the "Software"),
0006  * to deal in the Software without restriction, including without limitation
0007  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0008  * and/or sell copies of the Software, and to permit persons to whom the
0009  * Software is furnished to do so, subject to the following conditions:
0010  *
0011  * The above copyright notice and this permission notice shall be included in
0012  * all copies or substantial portions of the Software.
0013  *
0014  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0015  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0016  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0017  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
0018  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
0019  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
0020  * OTHER DEALINGS IN THE SOFTWARE.
0021  *
0022  * Authors: Karol Herbst <git@karolherbst.de>
0023  */
0024 #include "priv.h"
0025
0026 static char *nvkm_pcie_speeds[] = {
0027     "2.5GT/s",
0028     "5.0GT/s",
0029     "8.0GT/s",
0030 };
0031
0032 static enum nvkm_pcie_speed
0033 nvkm_pcie_speed(enum pci_bus_speed speed)
0034 {
0035     switch (speed) {
0036     case PCIE_SPEED_2_5GT:
0037         return NVKM_PCIE_SPEED_2_5;
0038     case PCIE_SPEED_5_0GT:
0039         return NVKM_PCIE_SPEED_5_0;
0040     case PCIE_SPEED_8_0GT:
0041         return NVKM_PCIE_SPEED_8_0;
0042     default:
0043         /* XXX 0x16 is 8_0, assume 0x17 will be 16_0 for now */
0044         if (speed == 0x17)
0045             return NVKM_PCIE_SPEED_8_0;
0046         return -1;
0047     }
0048 }
0049
0050 static int
0051 nvkm_pcie_get_version(struct nvkm_pci *pci)
0052 {
0053     if (!pci->func->pcie.version)
0054         return -ENOSYS;
0055
0056     return pci->func->pcie.version(pci);
0057 }
0058
0059 static int
0060 nvkm_pcie_get_max_version(struct nvkm_pci *pci)
0061 {
0062     if (!pci->func->pcie.version_supported)
0063         return -ENOSYS;
0064
0065     return pci->func->pcie.version_supported(pci);
0066 }
0067
0068 static int
0069 nvkm_pcie_set_version(struct nvkm_pci *pci, int version)
0070 {
0071     if (!pci->func->pcie.set_version)
0072         return -ENOSYS;
0073
0074     nvkm_trace(&pci->subdev, "set to version %i\n", version);
0075     pci->func->pcie.set_version(pci, version);
0076     return nvkm_pcie_get_version(pci);
0077 }
0078
0079 int
0080 nvkm_pcie_oneinit(struct nvkm_pci *pci)
0081 {
0082     if (pci->func->pcie.max_speed)
0083         nvkm_debug(&pci->subdev, "pcie max speed: %s\n",
0084                nvkm_pcie_speeds[pci->func->pcie.max_speed(pci)]);
0085     return 0;
0086 }
0087
0088 int
0089 nvkm_pcie_init(struct nvkm_pci *pci)
0090 {
0091     struct nvkm_subdev *subdev = &pci->subdev;
0092     int ret;
0093
0094     /* raise pcie version first */
0095     ret = nvkm_pcie_get_version(pci);
0096     if (ret > 0) {
0097         int max_version = nvkm_pcie_get_max_version(pci);
0098         if (max_version > 0 && max_version > ret)
0099             ret = nvkm_pcie_set_version(pci, max_version);
0100
0101         if (ret < max_version)
0102             nvkm_error(subdev, "couldn't raise version: %i\n", ret);
0103     }
0104
0105     if (pci->func->pcie.init)
0106         pci->func->pcie.init(pci);
0107
0108     if (pci->pcie.speed != -1)
0109         nvkm_pcie_set_link(pci, pci->pcie.speed, pci->pcie.width);
0110
0111     return 0;
0112 }
0113
0114 int
0115 nvkm_pcie_set_link(struct nvkm_pci *pci, enum nvkm_pcie_speed speed, u8 width)
0116 {
0117     struct nvkm_subdev *subdev = &pci->subdev;
0118     enum nvkm_pcie_speed cur_speed, max_speed;
0119     struct pci_bus *pbus;
0120     int ret;
0121
0122     if (!pci || !pci_is_pcie(pci->pdev))
0123         return 0;
0124     pbus = pci->pdev->bus;
0125
0126     if (!pci->func->pcie.set_link)
0127         return -ENOSYS;
0128
0129     nvkm_trace(subdev, "requested %s\n", nvkm_pcie_speeds[speed]);
0130
0131     if (pci->func->pcie.version(pci) < 2) {
0132         nvkm_error(subdev, "setting link failed due to low version\n");
0133         return -ENODEV;
0134     }
0135
0136     cur_speed = pci->func->pcie.cur_speed(pci);
0137     max_speed = min(nvkm_pcie_speed(pbus->max_bus_speed),
0138             pci->func->pcie.max_speed(pci));
0139
0140     nvkm_trace(subdev, "current speed: %s\n", nvkm_pcie_speeds[cur_speed]);
0141
0142     if (speed > max_speed) {
0143         nvkm_debug(subdev, "%s not supported by bus or card, dropping"
0144                "requested speed to %s", nvkm_pcie_speeds[speed],
0145                nvkm_pcie_speeds[max_speed]);
0146         speed = max_speed;
0147     }
0148
0149     pci->pcie.speed = speed;
0150     pci->pcie.width = width;
0151
0152     if (speed == cur_speed) {
0153         nvkm_debug(subdev, "requested matches current speed\n");
0154         return speed;
0155     }
0156
0157     nvkm_debug(subdev, "set link to %s x%i\n",
0158            nvkm_pcie_speeds[speed], width);
0159
0160     ret = pci->func->pcie.set_link(pci, speed, width);
0161     if (ret < 0)
0162         nvkm_error(subdev, "setting link failed: %i\n", ret);
0163
0164     return ret;
0165 }